Use of 2-Methylene-19-Nor-(20S)-1alpha,25-Dihydroxyvitamin D3 to Treat Secondary Hyperparathyroidism

ABSTRACT

Disclosed are methods of administering 2-methylene-19-nor-(20S)-1α,25-dihydroxyvitamin D 3  to treat and/or prevent secondary hyperparathyroidism and/or its accompanying symptoms in a subject having or at risk for developing secondary hyperparathyroidism.

CROSS-REFERENCE TO RELATED PATENT APPLICATIONS

The present application claims the benefit of priority under 35 U.S.C.§119(e) to U.S. Provisional Patent Application No. 61/666,264, filed onJun. 29, 2012, the content of which is incorporated herein by referencein its entirety.

BACKGROUND

This invention relates to vitamin D compounds useful in treating and/orpreventing secondary hyperparathyroidism and/or the symptoms thereof,and more particularly to the use of the vitamin D compound2-methylene-19-nor-(20S)-1α,25-dihydroxyvitamin D3 to treat and/orprevent secondary hyperparathyroidism and/or the symptoms thereof.

Renal disease has become an increasingly important health problem invirtually every country in the world including highly developedcountries such as the United States. Presently there are about 250,000patients on renal dialysis who have lost almost complete use of theirkidneys. There are approximately ten times this number of patients whohave lost some degree of renal function due to renal disease and areprogressing to complete renal failure. Renal failure is evidenced by adecreased glomeruli filtration rate (GFR) from a high value of 110ml/minute/1.73 m² to 30 ml/minute/1.73 m² where dialysis is ofteninitiated.

Many factors contribute to the development of renal disease. High bloodpressure is one of the significant contributors, as is having Type I orType II diabetes. Current treatments for renal failure are limited tohemodialysis, an extremely expensive procedure that currently issupported by federal governments because individuals typically cannotafford this procedure on their own. The annual cost of renal disease inthe United States alone is over $42 billion. Accordingly, effectivemethods for preventing renal disease and treating symptoms thereof wouldnot only provide a major health benefit but would also provide a majoreconomic benefit.

It is now universally accepted that vitamin D must first be25-hydroxylated in the liver and subsequently 1α-hydroxylated in thekidney before it can function. (See DeLuca, “Vitamin D: The vitamin andthe hormone,” Fed. Proc. 33, 2211-2219, 1974). These two reactionsproduce the final active form of vitamin D, namely 1α,25-(OH)₂D₃. (SeeDeLuca & Schnoes, “Vitamin D: Recent advances,” Ann. Rev. Biochem. 52,411-439, 1983). This compound then stimulates a number of physiologicalprocesses including: stimulating the intestine to absorb calcium,stimulating the kidney to reabsorb calcium, stimulating the intestine toabsorb phosphate, and stimulating bone to mobilize calcium when signaledby high parathyroid hormone (PTH) levels. These actions result in a risein plasma calcium and phosphorus levels that bring about the healing ofbone lesions such as rickets and osteomalacia and prevent theneurological disorder of hypocalcemic tetany.

Secondary hyperparathyroidism is a universal complication in patientswith chronic renal failure. Low levels of 1α,25-(OH)₂D₃ and phosphateretention are responsible for the development of secondaryhyperparathyroidism. Low levels of circulating 1α,25-(OH)₂D₃ are theresult of impaired kidney function resulting in the patient's inabilityto convert 25-hydroxy-vitamin D₃ to 1α,25-dihydroxyvitamin D₃. As aresult of low levels of circulating 1α,25-(OH)₂D₃, intestinal calciumabsorption is minimal which subsequently results in insufficient serumcalcium levels. When the parathyroid glands sense a low level of serumcalcium, the parathyroid glands secrete PTH which causes calcium to bemobilized from bone to regulate serum calcium. Left unchecked, thisabnormal secretion of PTH will lead to the development of renalosteodystrophy. High PTH levels can also lead to: 1) weakening of thebones; 2) calciphylaxis (when calcium forms clumps in the skin and leadto ulcers and potentially death of surrounding tissue); 3)cardiovascular complications; 4) abnormal fat and sugar metabolism; 5)itching (pruritis); and 6) low blood counts (anemia).

1α,25-dihydroxyvitamin D₃ has been used as a therapeutic forhyperparathyroidism in patients with renal diseases. In the treatment ofsecondary hyperparathyroidism of renal osteodystrophy, it is well knownthat 1α,25-dihydroxyvitamin D₃ binds to the vitamin D receptor (VDR)located in the parathyroid glands to suppress both growth andproliferation of the parathyroid cells and expression of thepreproparathyoid gene. (See Demay et al., “Sequences in the humanparathyroid hormone gene that bind the 1,25-dihydroxyvitamin D₃ receptorand mediate transcriptional repression in response to1,2S-hydroxyvitamin D₃.” Proc. Natl. Acad. Sci. USA 89, 8097-8101, 1992;and Darwish & DeLuca, “Identification of a transcription factor thatbinds to the promoter region of the human parathyroid hormone gene,”Arch. Biochem. Biophys. 365, 123-130, 1999). Because of its ability tosuppress parathyroid hormone (PTH), 1,25-(OH)₂D₃ has been used withsuccess in the treatment of secondary hyperparathyroidism. (SeeSlatopolsky et al., “Marked Suppression of Secondary Hyperparathyroidismby Intravenous Administration of 1,25-dihydroxycholecalciferol in UremicPatients,” J. Clin. Invest. 74:2136-2143, 1984). The use of1α,25-dihydroxyvitamin D₃ in the treatment of secondaryhyperparathyroidism of renal osteodystrophy is often precluded, however,by the development of hypercalcemia resulting from1α,25-dihydroxyvitamin D₃'s potent action on intestinal calciumabsorption and bone mineral calcium mobilization.

As noted previously, secondary hyperparathyroidism typically will occurin patients undergoing renal dialysis. Chronic renal failure is the mostcommon cause of secondary hyperparathyroidism. Failing kidneys do notconvert enough vitamin D to its active form and do not adequatelyexcrete phosphate. When this happens, insoluble calcium phosphate formsin the body and removes calcium from circulation. Ultimately, this leadsto hypocalcemia and secondary hyperparathyroidism.

Secondary hyperparathyroidism also can result from gastrointestinalmalabsorption syndromes (e.g., chronic pancreatitis, small boweldisease, and malabsorption-dependent bariatric surgery in which theintestines do not absorb vitamins and minerals properly), where thesesyndromes may result in insufficient absorption of the fat solublevitamin D. When vitamin D is insufficiently absorbed, hypocalcemia maydevelop and a subsequent increase in PTH secretion may result where thebody attempts to increase serum calcium levels. However, hypocalcemiaand secondary hyperparathyroidism also may appear in the early stages ofrenal disease due to low levels of 1,25(OH)₂D₃. Other less common causesof secondary hyperparathyroidism are long-term lithium therapy, vitaminD deficiency, malnutrition, vitamin D-resistant rickets, orhypermagnesemia (i.e., abnormally high blood magnesium levels).

Symptoms of secondary hyperparathyroidism include increased levels ofserum PTH, serum phosphorus, and serum creatinine. Less overt symptomsinclude bone and joint pain, bone deformities, broken bones (fractures),swollen joints, kidney stones, increased urination, muscle weakness andpain, nausea, and loss of appetite. Other less common symptoms includefatigue, upper abdominal pain, and depression.

Treatment of secondary hyperparathyroidism typically involves addressingthe underlying cause of the hypocalcemia. In patients with chronic renalfailure, treatment consists of dietary restriction of phosphorus,supplements with an active form of vitamin D such as calcitriol,Hectorol, or Zemplar® (paricalcitol), and phosphate binders which can bedivided into calcium-based binders and non-calcium based binders.

A newer class of medication is calcimimetics, one of which iscommercially available as Sensipar®(cinacalcet) in the United States andAustralia, and as Mimpara® in the European Union. Calcimimetics haveachieved positive responses and are FDA approved for use in patients ondialysis, but have not been approved for use in chronic kidney diseasepre-dialysis because, among other concerns, they can increase phosphoruslevels. Most patients with hyperparathyroidism secondary to chronickidney disease will improve after renal transplant, but many willcontinue to have a degree of residual hyperparathyroidism (i.e.,tertiary hyperparathyroidism) post-transplant with associated risk ofbone loss.

Although serum phosphorus is usually normal in patients with early renalinsufficiency, phosphate restriction can reduce secondaryhyperparathyroidism. Dietary phosphate restriction increases1,25-(OH)₂D₃ levels. (See Portale et al., “Effect of Dietary Phosphoruson Circulating Concentrations of 1,25-dihydroxyvitamin D andImmunoreactive Parathyroid Hormone in Children with Moderate RenalInsufficiency,” J. Clin. Invest. 73:1580-1589, 1984). This in turndecreases PTH by directly suppressing PTH gene transcription and byincreasing intestinal calcium absorption. In later stages of renalfailure, the extent of hyperparathyroidism and 1,25-(OH)₂D₃ deficiencyincreases, and phosphate restriction has little effect on 1,25-(OH)₂D₃levels. (See Lopez-Hilker et al., “Phosphorus Restriction ReversesHyperparathyroidism in Uremia Independent of Changes in Calcium andCalcitriol,” Am. J. Physiol. 259:F432-F437, 1990). This is presumablydue to the decreased renal mass available for 1,25-(OH)₂D₃ synthesis.

Several vitamin D analogs with low calcemic activity have been found tobe nearly as effective as 1,25-(OH)₂D₃ in suppressing PTH secretion bycultured bovine parathyroid cells. These include 22-oxacalcitriol (OCT),(Brown et al., “The Non-Calcemic Analog of Vitamin D, 22-oxacalcitriol(OCT) Suppresses Parathyroid Hormone Synthesis and Secretion,” J. Clin.Invest. 84:728-732, 1989), as well as 1,25-(OH)₂-16-ene-23-yne-D₃,1,25-(OH)₂-24-dihomo-D₃, and 1,25-(OH)₂-24-trihomo-22-ene-D₃.22-oxacalcitriol has been examined in detail for this action in vivo.(See Brown et al., “Selective Vitamin D Analogs and their TherapeuticApplications,” Sem. Nephrol 14:156-174, 1994, reporting that22-oxacalcitriol, despite its rapid clearance in viva, could suppressPTH mRNA). Low, submaximal doses of calcitriol and OCT exhibitedcomparable inhibition. OCT also has been shown to suppress serum PTH inuremic rats and dogs.

Another analog of 1,25-(OH)₂D₃ with low calcemic and phosphatemic actionis 19-nor-1,25-(OH)₂D₂. This analog of calcitriol has the carbon 28 andthe double bond at carbon 22 that are characteristic of vitamin D₂compounds, but it lacks carbon 19 and the exocyclic double bond found inall natural vitamin D compounds. Studies in vitro utilizing a primaryculture of bovine parathyroid cells demonstrated that19-nor-1,25-(OH)₂D₂ had a similar suppressive effect on PTH as1,25-(OH)₂D₃. A 52% suppression on PTH release was obtained with19-nor-1,25-(OH)₂D₂ at 10⁻⁷M. There was no significant difference in thesuppressive effect of PTH secretion between the two compounds.

Thereafter, preliminary studies were performed in vivo to determine thecalcemic activity of 19-nor-1,25-(OH)₂D2. It was found that 1,25-(OH)₂D₃(10 ng/at/10 days) increased serum calcium to the same magnitude as19-nor-1,25-(OH₂) D₂ (100 ng/rat/10 days). Because of this, threedifferent doses of 1,25-(OH)₂D₃ (2, 4, and 8 ng) and 19-nor-1,25-(OH)₂D₂(8, 25, and 75 ng) were selected for chronic studies. After two monthsof renal insufficiency, the animals received the above two compounds atthe three indicated doses, four times, during a period of eight days. Asexpected, 1,25-(OH)₂D₃ suppressed pre-pro-PTH mRNA and PTH secretion.However, this decrease was statistically significant only with a 8 ngdose, and this dose induced hypercalcemia and hyperphosphatemia. On theother hand, none of the doses of 19-nor-1,25-(OH)₂D2 producedstatistically significant changes in serum ionized calcium or serumphosphorus.

19-nor-1α,25(OH)₂D₂ is also known as Paricalcitol and19-nor-1α,25-dihydroxy-ergocalciferol. Paricalcitol injection isavailable commercially as Zemplar® from Abbott Laboratories, AbbottPark, Ill. A paricalcitol (Zemplar®) injection is described in U.S. Pat.No. 6,136,799 and has been approved by the FDA and is marketed for theprevention and treatment of secondary hyperparathyroidism associatedwith chronic renal failure (CKD Stage 5 or end-stage renal disease(ESRD), GFR <15 mL/min/1.73 m²). This intravenous formulation contains2-10 micrograms/milliliter of paricalcitol, 30% (v/v) propylene glycol,20% (v/v) ethanol and approximately 50% (v/v) water. Studies indicatethat paricalcitol injection suppresses elevated levels of PTH withminimal effect on serum calcium and phosphorus levels. Since itsapproval by the FDA in April of 1998, it is estimated that approximately200,000 patients have received at least one dose of paricalcitolinjection. Clinically, the safety and efficacy of paricalcitol injectionto treat secondary hyperparathyroidism are well established.

Hyperphosphatemia is also a persistent problem in chronic hemodialysispatients and can be further aggravated by therapeutic doses of1,25-(OH)₂D₃. (See Delmez et al., “Hyperphosphatemia: Its Consequencesand Treatment in Patients with Chronic Renal Disease,” Am. J. KidneyDis. 19:303-317, 1992; and Quarles et al., “Prospective trial of PulseOral versus Intravenous Calcitriol Treatment of Hyperparathyroidism inESRD,” Kidney Int. 45:1710-1721, 1994). In addition, the control ofphosphate absorption with large doses of calcium carbonate onlyincreases the risk of hypercalcemia from 1,25-(OH)₂D therapy. (SeeMeyrier et al., “The Influence of a High Calcium Carbonate Intake onBone Disease in Patients undergoing Hemodialysis,” Kidney Int.4:146-153, 1973; Moriniere et al., “Substitution of Aluminum Hydroxideby High Doses of Calcium Carbonate in Patients on Chronic Hemodialysis:Disappearance of Hyperaluminaemia and Equal Control ofHyperparathyroidism,” Proc. Eur. Dial Transplant Assoc. 19:784-787,1983; and Slatopolsky et al., “Calcium Carbonate as a Phosphate Binderin Patients with Chronic Renal Failure Undergoing Dialysis,” New Engl.J. Med. 315:157-161, 1986). Thus, an analog of 1,25-(OH)₂D₃ that cansuppress PTH with minor effects on calcium and phosphate metabolismwould be an ideal tool for the control and treatment of secondaryhyperparathyroidism.

Another vitamin D analog, namely,2-methylene-19-nor-(20S)-1α,25-dihydroxyvitamin D₃ (referred to in theliterature as “2MD”) is also known to suppress PTH production. (See U.S.Published Application No. 2011/0034426A1). Although it would thereforeappear to be a candidate for treating secondary hyperparathyroidism, itis also well known from U.S. Pat. No. 5,843,928 that 2MD has very potentcalcemic activity. 2MD significantly increases bone calcium mobilizationactivity to a level likely to be 10-100 times that of 1α,25-(OH)₂D₃while also exhibiting a modest increase in intestinal calcium transportactivity. Due to this highly selective activity for the mobilization ofcalcium from bone, the compound 2MD was never seriously considered as apharmaceutical agent for treating secondary hyperparathyroidism, untilnow.

SUMMARY

It has now been discovered that the vitamin D analog 2MD has the abilityto treat secondary hyperparathyroidism as well as symptoms of secondaryhyperparathyroidism when administered under well-controlled conditionsto a subject in need thereof. It also now been discovered that thevitamin D analog 2MD has the ability to prevent secondaryhyperparathyroidism as well as symptoms of secondary hyperparathyroidismwhen administered under well-controlled conditions to a subject in needthereof.

In one embodiment, the present invention provides a novel method oftreating secondary hyperparathyroidism by administering atherapeutically effective amount of a composition comprising2-methylene-19-nor-(20S)-1α,25-dihydroxyvitamin D₃ (2MD) orpharmaceutically acceptable salts thereof as the active agent to asubject exhibiting symptoms of secondary hyperparathyroidism, withoutinducing hypercalcemia in the subject.

In another embodiment, the present invention provides a novel method oftreating symptoms of secondary hyperparathyroidism by administering atherapeutically effective amount of a composition comprising2-methylene-19-nor-(20S)-1α,25-dihyroxyvitamin D₃ (2MD) orpharmaceutically acceptable salts thereof as the active agent to asubject exhibiting symptoms of secondary hyperparathyroidism, withoutinducing hypercalcemia in the subject.

In yet another embodiment, the present invention provides a novel methodof preventing secondary hyperparathyroidism by administering atherapeutically effective amount of a composition comprising2-methylene-19-nor-(20S)-1α,25-dihydroxyvitamin D₃ (2MD) orpharmaceutically acceptable salts thereof as the active agent to asubject at risk of developing secondary hyperparathyroidism, withoutinducing hypercalcemia in the subject.

In still another embodiment, the present invention provides a novelmethod of preventing symptoms of secondary hyperparathyroidism byadministering a therapeutically effective amount of a compositioncomprising of 2-methylene-19-nor-(20S)-1α,25-dihydroxyvitamin D₃ (2MD)or pharmaceutically acceptable salts thereof as the active agent to asubject at risk of developing secondary hyperparathyroidism, withoutinducing hypercalcemia in the subject.

In one embodiment, the 2-methylene-19-nor-(20S)-1α,25-dihydroxyvitaminD₃ is formulated in an oral, topical, transdermal, parenteral,injectable or infusable form to be administered in amounts ranging from10 ng/day to about 1 μg/day. Preferably, for the treatment of orprevention of secondary hyperparathyroidism, or for the treatment orprevention of the symptoms of secondary hyperparathyroidism, thecompound 2MD is administered either orally or parenterally (i.v.). Thedose may be properly selected in accordance with the specific route ofadministration. Suitable doses may include doses within the range ofabout 10 ng to about 1 ug per day. Preferably a dose is administeredthree times per week either intravenously or orally to subjectsreceiving hemodialysis treatment.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 schematically illustrates the intraperitoneal treatment protocolwith 2MD contemplated herein.

FIG. 2 is a graph illustrating the effect of intraperitonealadministration of 2MD at various doses on serum PTH in a uremic ratmodel.

FIG. 3 is a graph illustrating the effect of intraperitonealadministration of 2MD at various doses on serum calcium in a uremic ratmodel.

FIG. 4 schematically illustrates the oral treatment protocol with 2MDcontemplated herein.

FIG. 5 is a graph illustrating the effect of oral administration of 2MDat various doses on serum PTH in a uremic rat model.

FIG. 6 is a graph illustrating the effect of oral administration of19-nor-1α,25-dihdroxyvitamin D: (marketed under the tradename Zemplar®)at various doses on serum PTH in a uremic rat model.

FIG. 7 is a graph illustrating the effect of oral administration of 2MDat various doses on serum calcium in a uremic rat model.

FIG. 8 is a graph illustrating the effect of oral administration of19-nor-1α,25-dihydroxyvimtin D)₂ (marketed under the tradename Zemplar®)at various doses on serum PTH in a uremic rat model.

FIG. 9 is a graph illustrating the effect of oral administration of 2MDat various doses on serum phosphorus in a uremic rat model.

FIG. 10 is a graph illustrating the effect of oral administration of19-nor-1α,25-dihydroxyvimtin D₂ (marketed under the tradename Zemplar®)at various doses on serum phosphorus in a uremic rat model.

FIG. 11 is a graph illustrating the effect of oral administration of 2MDat various doses on serum creatinine in a uremic rat model.

FIG. 12 is a graph illustrating the effect of oral administration of19-nor-1α,25-dihydroxyvimtin D₂ (marketed under the tradename Zemplar®)at various doses on serum creatinine in a uremic rat model.

FIG. 13 is a graph illustrating the effect of oral administration of 2MDat various doses on serum PTH in a Phase I B human trial ofpostmenopausal women.

DETAILED DESCRIPTION

Disclosed are methods of treating and/or preventing secondaryhyperparathyroidism or the symptoms thereof. The disclosed methodsfurther may described as follows based on the following definitions.

Unless defined otherwise, all technical and scientific terms used hereinhave the same meanings as commonly understood by one of ordinary skillin the art to which this invention belongs. All publications and patentsspecifically mentioned herein are incorporated by reference in theirentirety for all purposes including describing and disclosing thechemicals, instruments, statistical analyses and methodologies which arereported in the publications which might be used in connection with theinvention. All references cited in this specification are to be taken asindicative of the level of skill in the art. Nothing herein is to beconstrued as an admission that the invention is not entitled to antedatesuch disclosure by virtue or prior invention.

In the specification and in the claims, the terms “including” and“comprising” are open-ended terms and should be interpreted to mean“including, but not limited to.” These terms encompass the morerestrictive terms “consisting essentially of” and “consisting of.” It isalso to be noted that the terms “comprising,” “including,”“characterized by” and “having” can be used interchangeably.

As used herein and in the appended claims, the singular forms “a,” “an,”and “the” include plural reference unless the context clearly dictatesotherwise. As well, the terms “a” (or “an”), “one or more” and “at leastone” can be used interchangeably herein.

Where a range of values is provided, it is understood that eachintervening value, and any combination or subcombination of interveningvalues, between the upper and lower limit of that range and any otherstated or intervening value in that stated range, is encompassed withinthe range of values recited.

Certain ranges are presented herein with numerical values being precededby the term “about.” The term “about” is used herein to provide literalsupport for the exact number that it precedes, as well as a number thatis near to or approximately the number that the term precedes. Indetermining whether a number is near to or approximately a specificallyrecited number, the near or approximating unrecited number may be anumber which, in the context in which it is presented, provides thesubstantial equivalent of the specifically recited number, and thus willtypically refer to a number or value that is 10% below or above thespecifically recited number or value.

The disclosed methods may be utilized to treat and/or prevent secondaryhyperthyroidism in a patient in need thereof. A patient in need thereofmay include, but is not limited to, a patient having or at risk fordeveloping secondary hyperthyroidism subsequent to a renal disease ordisorder. A patient in need thereof may include, but is not limited to,a patient having or at risk for developing secondary hyperthyroidismsubsequent to renal osteodystrophy, for example, due to renal failure. Apatient in need thereof may include a patient undergoing renal dialysis.A patient in need thereof may include, but is not limited to, a patienthaving or at risk for developing secondary hyperthyroidism as a resultof a gastrointestinal malabsorption syndromes (e.g., chronicpancreatitis, small bowel disease, and malabsorption-dependent bariatricsurgery in which the intestines do not absorb vitamins and mineralsproperly). A patient in need thereof may include, but is not limited to,a patient having or at risk for developing secondary hyperthyroidism asa result of a long-term lithium therapy, vitamin D deficiency,malnutrition, vitamin D-resistant rickets, or hypermagnesemia (i.e.,abnormally high blood magnesium levels).

The disclosed methods may be utilized to treat and/or prevent thesymptoms of secondary hyperthyroidism in a patient in need thereof.Symptoms of secondary hyperthyroidism treated and/or prevented by thedisclosed methods may include, but are not limited to: weakening of thebones; calciphylaxis (when calcium forms clumps in the skin and lead toulcers and potentially death of surrounding tissue); cardiovascularcomplications; abnormal fat and sugar metabolism; itching (pruritis);and low blood counts (anemia). Other symptoms of secondaryhyperthyroidism treated and/or prevented by the disclosed methods mayinclude: increased levels of serum PTH, serum phosphorus, and serumcreatinine. Further symptoms of secondary hyperthyroidism treated and/orprevented by the disclosed methods may include: bone and joint pain,bone deformities, broken bones (fractures), swollen joints, kidneystones, increased urination, muscle weakness and pain, nausea, and lossof appetite. Even further symptoms of secondary hyperthyroidism treatedand/or prevented by the disclosed methods may include: fatigue, upperabdominal pain, and depression.

Previously, it has been demonstrated that 300 ng per day of1α,25-dihydroxyvitamin D₃ (1,25(OH₂D₃) administered through the diet caneffectively prevent renal disease and renal failure by reducing thesymptoms of renal disease. (See James Wonkee Kim. Effects of1α,25-dihydroxyvitamin D₃ on the MRL/MpJ-fas/lpr model of systemic lupuserythematosus (Ph.D. Thesis, University of Wisconsin-Madison (2009)).

For instance, it has been previously shown that administering1α,25-dihydroxyvitamin D₃-(1,25(OH)₂D₃) completely prevents proteinuriain the MRL/MpJ-FAS^(lpr) (MRL/lpr) mouse model of systemic lupuserythematosus (SLE). (See id.). However, severe hypercalcemia alwaysaccompanied this treatment. Hypercalcemia (i.e., increased levels ofcalcium in the blood) can result in serious physical problems, includingdeath. Specifically, an increase in calcium of approximately 2 mg/100 mlis considered mild hypercalcemia and is not considered a problem.However, an increase in calcium levels of more than 2 mg/100 ml isconsidered severe hypercalcemia and can cause calcification of thekidney, heart, and aorta. Clearly, the use of this compound is notoptimal to treat or prevent secondary hyperparathyroidism, or thesymptoms thereof, because of the resultant hypercalcemia.

2-methylene-19-nor-(20S)-1α,25-dihydroxyvitamin D₃ (2MD) is an analog of1,25(OH)₂D₃ which has been shown to have increased in vivo potencytoward bone but not on intestinal calcium absorption. The overallsynthesis of 2MD is illustrated and described more completely in U.S.Pat. No. 5,843,928, issued Dec. 1, 1998, and entitled“2-Alkylidene-19-Nor-Vitamin D Compounds” the specification of which isspecifically incorporated herein by reference. The biological activityof 2MD is also reported in U.S. Pat. No. 5,843,928 and in Shevde et al.,“A Potent Analog of 1α,25-dihydroxyvitamin D₃ Selectively Induces BoneFormation” PNAS, Vol. 99, No. 21 pp 13487-13491 (2002), both of whichare specifically incorporated herein by reference.

In the methods disclosed herein, 2MD can be administered to treat and/orprevent secondary hyperparathyroidism and/or its accompanying symptomswithout causing severe hypercalcemia, while also resulting in reducedlevels of phosphorus and creatinine in blood as well as decreased PTHlevels in the blood.

Also in the methods disclosed herein, 2MD can be used to treat andreduce the severity of secondary hyperparathyroidism of renal diseaseand its accompanying symptoms, without causing severe hypercalcemia, byreducing phosphorus, creatinine and PTH levels in blood.

As used herein, “hypercalcemia” means elevated calcium levels in theblood of more than 2 mg/100 ml. In a normal subject, calcium levels areapproximately 9-10.5 mg/dL or 2.2-2.6 mmol/L. In cases of severehypercalcemia (i.e., calcium levels above 15-16 mg/dL or 3.75-4 mmol/L)coma and cardiac arrest can develop.

The present invention therefore provides novel methods of treatingand/or preventing secondary hyperparathyroidism and/or its accompanyingsymptoms in a subject at risk of developing secondaryhyperparathyroidism, and of treating and/or preventing secondaryhyperparathyroidism and/or its accompanying symptoms in a subjectexhibiting symptoms of secondary hyperparathyroidism, by administeringto the subject a therapeutically effective amount of2-methylene-19-nor-(20S)-1α,25-dihydroxyvitamin D₃ (2MD) orpharmaceutically acceptable salts thereof without inducing hypercalcemiain the subject, where 2MD has the structure (I):

As used herein, “preventing” means forestalling of a clinical symptomindicative of secondary hyperparathyroidism. Such forestalling includes,for example, the maintenance of normal kidney functions in a subject atrisk of developing secondary hyperparathyroidism prior to thedevelopment of overt symptoms of secondary hyperparathyroidismincluding, but not limited to, increased levels of serum PTH, phosphorusand creatinine. Therefore, the term “preventing” includes theprophylactic treatment of subjects to guard them from the occurrence ofsecondary hyperparathyroidism. Preventing secondary hyperparathyroidismin a subject is also intended to include inhibiting or arresting thedevelopment of secondary hyperparathyroidism. Inhibiting or arrestingthe development of secondary hyperparathyroidism includes, for example,inhibiting or arresting the occurrence of increased levels of serum PTH,phosphorus and creatinine.

As used herein, a “renal disease” or a “renal disorder” means acondition exhibiting impaired kidney function in a subject who is not ondialysis or a patient with chronic kidney disease (CKD) at stages 2 or3, such as, for instance, acute kidney failure, acute nephriticsyndrome, analgesic nephropathy, atheroembloic renal disease, chronickidney failure, chronic nephritis, congenital nephrotic syndrome,goodpasture syndrome, interstitial nephritis, kidney cancer, kidneydamage, kidney infection, kidney injury, kidney stones,membranoproliferative GNI, membranoproliferative GNII, membranousnephropathy, minimal change disease, necrotizing glomerulonephritis,nephroblastoma, nephrocalcinosis, nephrogenic diabetes insipidus,nephropathy-IgA, nephrosis nephrotic syndrome, polycystic kidneydisease, post-strepococcal GN, reflux nephropathy, renal arteryembolism, renal artery stenosis, renal disorders, renal papillarynecrosis, renal tubular acidosis type I, renal tubular acidosis type II,renal underperfusion, renal vein thrombosis.

“Renal disease” is also meant to include patients with establishedkidney failure (e.g., a glomerular filtration rate (GFR) of less than 15mL/min/1.73 m² or permanent renal replacement therapy (RRT)). A subjecthaving “renal disease” is meant to include a subject who has had kidneydamage for more than 3 months, as defined by structural or functionalabnormalities of the kidney, with or without decreased GFR, manifestedby either pathological abnormalities or markers of kidney damage,including abnormalities in the composition of the blood or urine, orabnormalities in imaging tests. Markers of kidney damage includeproteinuria of greater than 300 μg/day as measured by 24-HR excretionmethod. (See Table 15, Am. J. of Kidney Diseases, v.39, no. 2, Suppl. 1(February 2002), pp. 546-575, incorporated herein by reference). Thisdefinition may include patients on dialysis.

As used herein, a patient having “stage 2 chronic kidney disease (CKD)”means a patient exhibiting a mild reduction in GFR (60-89 mL/min/1.73m²). Kidney damage is defined as pathologic abnormalities or markers ofdamage, including abnormalities in blood or urine test or imagingstudies. A patient having “stage 3 chronic kidney disease (CKD)” means apatient exhibiting a moderate reduction in GFR (30-59 mL/min/1.73 m²).Guidelines for characterizing kidney disease may distinguish betweenstage 3A (GFR 45-59) and stage 3B (GFR 30-44) for purposes of screeningand referral. For more information about stages of kidney disease, seeAm. J. of Kidney Disease, V. 39, No. 2, Suppl. 1, February 2002,incorporated herein by reference.

As used herein, a “subject” includes mammals and non-mammals. “Mammals”means any member of the class Mammalia including, but not limited to,humans, non-human primates such as chimpanzees and other apes and monkeyspecies; farm animals such as cattle, horses, sheep, goats, and swine;domestic animals such as rabbits, dogs, and cats; laboratory animalsincluding rodents, such as rats, mice, and guinea pigs; and the like.Examples of non-mammals include, but are not limited to, birds, and thelike. The term “subject” does not denote a particular age or sex. Theprimary subjects to which the present invention is directed are theclass of humans being treated with, or receiving, hemodialysis. The term“subject” may be utilized herein interchangeably with the terms“patient” or “individual.”

As used herein, “administering” mean introducing a compound into thebody, preferably into the systemic circulation, as described in moredetail below. Examples include but are not limited to oral, topical,buccal, sublingual, pulmonary, transdermal, transmucosal, as well assubcutaneous, intraperitoneal, intravenous, and intramuscular injectionor in the form of liquid or solid doses via the alimentary canal.

As used herein, “therapeutically effect” means an amount of a compoundthat, when administered to a subject for treating or preventing adisease, is sufficient to effect such treatment of prevention of thedisease. A “therapeutically effective amount” will vary depending on thecompound, the disease state being treated, the severity or the diseasetreated, the age and relative health of the subject, the route and formof administration, the judgment of the attending medical or veterinarypractitioner, and other factors. As disclosed herein, male weanlingHarlan-Sprague Dawley rats were administered several dose levels of 2MDthat would not cause significant hypercalcemia. We found that 2½nanograms/kilogram body weight (ng/kg bw) of 2MD per rat per day issufficient to prevent and treat secondary hyperparathyroidism, or toprevent or treat symptoms of secondary hyperparathyroidism, withoutincreasing serum calcium levels. Furthermore, 400 ng per day of 2MD inpostmenopausal women showed over a 60% reduction in serum PTH levelswhile maintaining serum calcium levels within the physiologically normalrange (FIG. 13).

In one embodiment, the therapeutically effective amount ranges frombetween about 10 ng/day to about 1 μg/day, and preferably from betweenabout 20 ng/day to about 1 μg/day. In a more preferred embodiment, thetherapeutically effective amount ranges from between about 40 ng/day toabout 600 ng/day, or between about 50 ng/day to about 600 ng/day. In themost preferred embodiment, the therapeutically effective amount rangesfrom between about 100 ng/day to about 400 ng/day.

As used herein, “treat,” “treating” or “treatment” means amelioration,alleviation or abation of a clinical symptom indicative of secondaryhyperparathyroidism. Amelioration, alleviation or abation of a clinicalsymptom includes, for example, arresting, reducing the severity of orslowing the progression of or causing the regression of a symptom ofsecondary hyperparathyroidism. For instance, lowering the amount ofserum PTH, serum phosphorus or serum creatinine levels in response totreatment with 2MD. Specifically, treating may include reducing theamount of serum PTH, serum phosphorus or serum creatinine by at leastabout 20%. In one embodiment, the amount of serum PTH, serum phosphorusor serum creatinine in the subject's blood is reduced by about 20-40% orabout 35-50%. Other pathological conditions, chronic complications orphenotypic manifestations of secondary hyperparathyroidism are known tothose skilled in the art and can similarly be used as a measure oftreating secondary hyperparathyroidism so long as there is a reductionin the severity of the condition, complication or manifestationassociated with the disease.

Effective compound formulations are described in U.S. Pat. No. 5,843,928and include pharmaceutical applications as a solution in innocuoussolvents, or as an emulsion, suspension or dispersion in suitablesolvents or carriers, or as pills, tablets, capsules combined with solidcarriers. Other formulations may also include other pharmaceuticallyacceptable and nontoxic excipients such as stabilizers, anti-oxidants,binders, coloring agents or emulsifying or taste-modifying agents andextended release formulations.

In one embodiment, the 2MD compound is the active pharmaceuticalingredient (API) administered in the disclosed methods. The API may beformulated in an oral pharmaceutical dosage form as a solution ininnocuous solvents, emulsion, suspension or dispersion in suitablesolvents or carriers. The API may also be formulated in various oraldosage forms, such as pills, tablets or capsules using suitablepharmaceutical solid carriers. Such pharmaceutical formulations may alsocontain other pharmaceutically suitable USP-approved inactiveingredients, excipients, such as stabilizers, anti-oxidants, binders,coloring agents, emulsifiers, and/or taste-modifying agents, which arereferred to as USP approved inactive pharmaceutical ingredients.

The API may be administered orally, topically, parenterally ortransdermally or by inhalation. The compound may be administered byinjection or intravenous infusion using suitable sterile solutions.Topical dosage forms may be creams, ointments, patches, or similarvehicles suitable for transdermal and topical dosage forms.

In some embodiments, the API may be formulated in doses for delivering adose ranging from between about long/day to about 1 μg/day, preferablefrom between about 20 ng/day to about 1 μg/day, and more preferably frombetween about 40 ng/day to about 600 ng/day, or from between about 50 ngto about 600 ng per day and most preferably from between about 100ng/day to about 400 ng/day. The API preferably is formulated in a dosethat may be used for the prevention or treatment of secondaryhyperparathyroidism, or for the prevention or treatment of symptoms ofsecondary hyperparathyroidism. Typically, the positive effects of 2MDare observed at dose levels that do not significantly raise serumcalcium. Such dose and dosing regimens may be adjusted to accommodatedisease severity or progression, patientpredisposition/at-risk/susceptible-to and other known criteria.

The pharmaceutically suitable oral carrier systems (also referred to asdrug delivery systems, which are modern technology, distributed with oras a part of a drug product that allows for the uniform release ortargeting or drugs to the body) preferably include FDA-approved and/orUSP-approved inactive ingredients. Under 21 CFR 210.3(b)(8), an inactiveingredient is any component of a drug product intended to furnishpharmaceutical activity or other direct effect in the diagnosis, or toaffect the structure or any function of the body of humans or otheranimal. Active ingredients include those components of the product thatmay undergo chemical change during the manufacture of the drug productand be present in the drug product in a modified form intended tofurnish the specified activity or effect. As use herein, a kit (alsoreferred to as a dosage form) is a packaged collection of relatedmaterial.

As used herein, “oral dosage” forms may include capsules (i.e., a solidoral dosage form consisting of a shell and a filling), whereby the shellis composed of a single sealed enclosure, or two halves that fittogether and which are sometimes sealed with a band, and whereby capsuleshells may be made from gelatin, starch, or cellulose, or other suitablematerials, may be soft or hard, and are filled with a solid or liquidingredients that can be poured or squeezed. The oral dosage form mayalso be a capsule or coated pellets, in which the drug is enclosedwithin either a hard or soft soluble container or “shell” made from asuitable form of gelatin. The drug itself may be in the form of granulesto which varying amount of coating have been applied or in a capsulecoated extended release, in which the drug is enclosed within either ahard or soft soluble container or “shell” made from a suitable form ofgelatin. Additionally, the capsule may be covered in a designatedcoating which releases a drug or drugs in such a manner to allow atleast a reduction in dosing frequency as compared to that drug or drugspresented as a conventional dosage form.

The oral dosage form may further be a capsule delayed release, in whichthe drug is enclosed within either a hard or soft soluble container madefrom a suitable form of gelatin, and which releases a drug (or drugs) ata time other than promptly after administration, whereby enteric-coatedarticles are delayed release dosage forms. Capsule delayed releasepellets, in which the drug is enclosed within either a hard or softcontainer or “shell” are also useful. In these cases, the drug itself isin the form of granules to which enteric coating has been applied, thusdelaying release of the drug until its passing into the intestine.Capsule extended release and capsule film-coated extended release arealso useful.

Additionally, the capsule is covered in a designated film coating, andwhich releases a drug or drugs in such a manner to allow at least areduction in dosing frequency as compared to that drug or drugspresented as a conventional dosage form), capsule gelatin coated (asolid dosage form in which the drug is enclosed within either a hard orsoft soluble container made from a suitable form of gelatin; through abanding process, the capsule is coated with additional layers of gelatinso as to form a complete seal), capsule liquid filled (a solid dosageform in which the drug is enclosed within a soluble, gelatin shell whichis plasticized by the addition of a polyol, such as sorbitol orglycerin, and is therefore of a somewhat thicker consistency than thatof a hard shell capsule).

Typically, the active ingredients may be dissolved or suspended in aliquid vehicle, a granule (a small particle or grain), a pellet (a smallsterile solid mass consisting of a highly purified drug, with or withoutexcipients, made by the formation of granules, or by compression andmolding), or a pellet coated extended release (a solid dosage form inwhich the drug itself is in the form of granules to which varyingamounts of coating have been applied, and which releases a drug or drugsin such a manner to allow a reduction in dosing frequency as compared tothat drug or drugs presented as a conventional dosage form).

Other forms include pills (a small, round solid dosage form containing amedicinal agent intended for oral administration), powder (an intimatemixture of dry, finely divided drugs and/or chemicals that may beintended for internal or external use), elixir (a clear, pleasantlyflavored, sweetened hydroalcoholic liquid containing dissolved medicinalagents; it is intended for oral use), chewing gum (a sweetened andflavored insoluble plastic material of various shapes which when chewed,releases a drug substance into the oral cavity), syrup (an oral solutioncontaining high concentrations of sucrose or other sugars; the term hasalso been used to include any other liquid dosage form prepared in asweet and viscid vehicle, including oral suspensions), tablet (a soliddosage form containing medicinal substances with or without suitablediluents), tablet chewable (a solid dosage form containing medicinalsubstances with or without suitable diluents that is intended to bechewed, producing a pleasant tasting residue in the oral cavity that iseasily swallowed and does not leave a bitter or unpleasant after-taste),tablet coated or tablet delayed release, tablet dispersible, tableteffervescent, tablet extended release, tablet film coated, or tabletfilm coated extended release where the tablet is formulated in suchmanner as to make the contained medicament available over an extendedperiod of time following ingestion.

In other forms, a tablet for solution, tablet for suspension, tabletmultilayer, tablet multilayer extended release may be provided, wherethe tablet is formulated in such manner as to allow at least a reductionin dosing frequency as compared to that drug presented as a conventionaldosage form. A tablet orally disintegrating, tablet orallydisintegrating delayed release, tablet soluble, tablet sugar coated,osmotic, and the like are also suitable.

The oral dosage form composition may contain an active pharmaceuticalingredient and one or more inactive pharmaceutical ingredients such asdiluents, solubilizers, alcohols, binders, controlled release polymers,enteric polymers, disintegrants, excipients, colorants, flavorants,sweeteners, antioxidants, preservatives, pigments, additives, fillers,suspension agents, surfactants (e.g., anionic, cationic, amphoteric andnonionic), and the like. Various FDA-approved topical inactiveingredients are found at the FDA's “The Inactive Ingredients Database”that contains inactive ingredients specifically intended as such by themanufacturer, whereby inactive ingredients can also be considered activeingredients under certain circumstances, according to the definition ofan active ingredient given in 21 CFR 210.3(b)(7). Alcohol is a goodexample of an ingredient that may be considered either active orinactive depending on the product formulation.

As used herein, the injectable and infusion dosage forms include, butare not limited to, a liposomal injectable, which either consists of orforms liposomes (a lipid bilayer vesicle usually composed ofphospholipids which is used to encapsulate an active drug substance). Aninjection, which includes a sterile preparation intended for parenteraluse; five distinct classes of injections exist as defined by the USP, isalso suitable. An emulsion injection, which includes an emulsionconsisting of a sterile, pyrogen-free preparation intended to beadministered parenterally or a lipid complex injection are alsosuitable.

Other forms include a powder for solution injection, which is a sterilepreparation intended for reconstitution to form a solution forparenteral use; a powder for suspension injection that is a sterilepreparation intended for reconstitution to form a suspension forparenteral use; a powder lyophilized for liposomal suspension injection,which is a sterile freeze dried preparation intended for reconstitutionfor parenteral use which has been formulated in a manner that wouldallow liposomes (a lipid bilayer vesicle usually composed ofphospholipids which is used to encapsulate an active drug substance,either within a lipid bilayer or in an aqueous space) to be formed uponreconstitution; a powder lyophilized for solution injection, which is adosage form intended for the solution prepared by lyophilization(“freeze drying”), a process which involves the removal of water fromproducts in the frozen state at extremely low pressures.

This is intended for subsequent addition of liquid to create a solutionthat conforms in all respects to the requirements for injections; apowder lyophilized for suspension injection being a liquid preparation,intended for parenteral use that contains solids suspended in a suitablefluid medium and conforms in all respects to the requirements forSterile Suspensions; the medicinal agents intended for the suspensionare prepared by lyophilization (“freeze drying”), a process whichinvolves the removal of water from products in the frozen state atextremely low pressures; a solution injection being a liquid preparationcontaining one or more drug substances dissolved in a suitable solventor mixture of mutually miscible solvents that is suitable for injection;a solution concentrate injection being a sterile preparation forparenteral use which, upon the addition of suitable solvents, yields asolution conforming in all respects to the requirements for injections.

A suspension injection comprises a liquid preparation, suitable forinjection, which consists of solid particles dispersed throughout aliquid phase in which the particles are not soluble that can alsoconsist of an oil phase dispersed throughout an aqueous phase, orvice-versa. A suspension liposomal injection comprises a liquidpreparation, suitable for injection, which consists of an oil phasedispersed throughout an aqueous phase in such a manner that liposomes (alipid bilayer vesicle usually composed of phospholipids which is used toencapsulate an active drug substance, either within a lipid bilayer orin an aqueous space) are formed. A suspension sonicated injectioncomprises a liquid preparation, suitable for injection, which consistsof solid particles dispersed throughout a liquid phase in which theparticles are not soluble. In addition, the product is sonicated while agas is bubbled through the suspension, and this results in the formationof microspheres by the solid particles.

The parenteral carrier system includes one or more pharmaceuticallysuitable excipients, such as solvents and co-solvents, solubilizingagents, wetting agents, suspending agents, thickening agents,emulsifying agents, chelating agents, buffers, pH adjusters,antioxidants, reducing agents, antimicrobial preservatives, bulkingagents, protectants, tonicity adjusters, and special additives.Formulations suitable for parenteral administration convenientlycomprise a sterile oily or aqueous preparation of the active ingredientwhich is preferably isotonic with the blood of the recipient.

As used herein, inhalation dosage forms include, but are not limited to,aerosol being a product that is packaged under pressure and containstherapeutically active ingredients that are released upon activation ofan appropriate valve system intended for topical application to the skinas well as local application into the nose (nasal aerosols), mouth(lingual and sublingual aerosols), or lungs (inhalation aerosols); foamaerosol being a dosage form containing one or more active ingredients,surfactants, aqueous or nonaqueous liquids, and the propellants, wherebyif the propellant is in the internal (discontinuous) phase (i.e., of theoil-in-water type), a stable foam is discharged, and if the propellantis in the external (continuous) phase (i.e., of the water-in-oil type),a spray or a quick-breaking foam is discharged; metered aerosol being apressurized dosage form consisting of metered dose valves which allowfor the delivery of a uniform quantity of spray upon each activation;powder aerosol being a product that is packaged under pressure andcontains therapeutically active ingredients, in the form of a powder,that are released upon activation of an appropriate valve system; and,aerosol spray being an aerosol product which utilizes a compressed gasas the propellant to provide the force necessary to expel the product asa wet spray and being applicable to solutions of medicinal agents inaqueous solvents.

As used herein, transdermal dosage form includes, but is not limited to,a patch being a drug delivery system that often contains an adhesivebacking that is usually applied to an external site on the body, wherebythe ingredients either passively diffuse from, or are activelytransported from, some portion of the patch, and whereby depending uponthe patch, the ingredients are either delivered to the outer surface ofthe body or into the body; and, other various types of transdermalpatches such as matrix, reservoir and others known in the art.

As used herein, the topical dosage form includes various dosage formsknown in the art such as lotions (an emulsion, liquid dosage form,whereby this dosage form is generally for external application to theskin), lotion augmented (a lotion dosage form that enhances drugdelivery, whereby augmentation does not refer to the strength of thedrug in the dosage form), gels (a semisolid dosage form that contains agelling agent to provide stiffness to a solution or a colloidaldispersion, whereby the gel may contain suspended particles) andointments (a semisolid dosage form, usually containing less than 20%water and volatiles and greater than 50% hydrocarbons, waxes, or polyolsas the vehicle, whereby this dosage form is generally for externalapplication to the skin or mucous membranes).

Ointment augmented (an ointment dosage form that enhances drug delivery,whereby augmentation does not refer to the strength of the drug in thedosage form), creams (an emulsion, semisolid dosage form, usuallycontaining greater than 20% water and volatiles and/or less than 50%hydrocarbons, waxes, or polyols may also be used as the vehicle, wherebythis dosage form is generally for external application to the skin ormucous membranes. Cream augmented (a cream dosage form that enhancesdrug delivery, whereby augmentation does not refer to the strength ofthe drug in the dosage form), emulsions (a dosage form consisting of atwo-phase system comprised of at least two immiscible liquids, one ofwhich is dispersed as droplets, internal or dispersed phase, within theother liquid, external or continuous phase, generally stabilized withone or more emulsifying agents, whereby emulsion is used as a dosageform term unless a more specific term is applicable, e.g. cream, lotion,ointment), suspensions (a liquid dosage form that contains solidparticles dispersed in a liquid vehicle), suspension extended release,pastes (a semisolid dosage form, containing a large proportion, 20-50%,of solids finely dispersed in a fatty vehicle, whereby this dosage formis generally for external application to the skin or mucous membranes),solutions (a clear, homogeneous liquid dosage form that contains one ormore chemical substances dissolved in a solvent or mixture of mutuallymiscible solvents), and powders are also suitable.

Shampoos (a lotion dosage form which has a soap or detergent that isusually used to clean the hair and scalp) are often used as a vehiclefor dermatologic agents. For instance, shampoo suspensions (a liquidsoap or detergent containing one or more solid, insoluble substancesdispersed in a liquid vehicle that is used to clean the hair and scalpand is often used as a vehicle for dermatologic agents) are often used.Aerosol foams (i.e., a dosage form containing one or more activeingredients, surfactants, aqueous or nonaqueous liquids, and thepropellants; if the propellant is in the internal discontinuous phase,i.e., of the oil-in-water type, a stable foam is discharged, and if thepropellant is in the external continuous phase, i.e., of thewater-in-oil type, a spray or a quick-breaking foam is discharged),sprays (a liquid minutely divided as by a jet of air or steam), meteredspray (a non-pressurized dosage form consisting of valves which allowthe dispensing of a specified quantity of spray upon each activation),and suspension spray (a liquid preparation containing solid particlesdispersed in a liquid vehicle and in the form of coarse droplets or asfinely divided solids to be applied locally, most usually to thenasal-pharyngeal tract, or topically to the skin) are also suitable.

Jellies (a class of gels, which are semisolid systems that consist ofsuspensions made up of either small inorganic particles or large organicmolecules interpenetrated by a liquid—in which the structural coherentmatrix contains a high portion of liquid, usually water) and films (athin layer or coating), including film extended release (a drug deliverysystem in the form of a film that releases the drug over an extendedperiod in such a way as to maintain constant drug levels in the blood ortarget tissue) and film soluble (a thin layer or coating which issusceptible to being dissolved when in contact with a liquid) are alsosuitable.

Sponges (a porous, interlacing, absorbent material that contains a drug,whereby it is typically used for applying or introducing medication, orfor cleansing, and whereby a sponge usually retains its shape), swabs (asmall piece of relatively flat absorbent material that contains a drug,whereby a swab may also be attached to one end of a small stick, andwhereby a swab is typically used for applying medication or forcleansing).

Patches (a drug delivery system that often contains an adhesive backingthat is usually applied to an external site on the body, whereby itsingredients either passively diffuse from, or are actively transportedfrom, some portion of the patch, whereby depending upon the patch, theingredients are either delivered to the outer surface of the body orinto the body, and whereby a patch is sometimes synonymous with theterms ‘extended release film’ and ‘system’), patch extended release (adrug delivery system in the form of a patch that releases the drug insuch a manner that a reduction in dosing frequency compared to that drugpresented as a conventional dosage form, e.g., a solution or a promptdrug-releasing, conventional solid dosage form), patch extended releaseelectronically controlled (a drug delivery system in the form of a patchwhich is controlled by an electric current that releases the drug insuch a manner that a reduction in dosing frequency compared to that drugpresented as a conventional dosage form, e.g., a solution or a promptdrug-releasing, conventional solid dosage form), and the like. Thevarious topical dosage forms may also be formulated as immediaterelease, controlled release, sustained release, or the like.

The topical dosage form composition contains an active pharmaceuticalingredient and one or more inactive pharmaceutical ingredients such asexcipients, colorants, pigments, additives, fillers, emollients,surfactants (e.g., anionic, cationic, amphoteric and nonionic),penetration enhancers (e.g., alcohols, fatty alcohols, fatty acids,fatty acid esters and polyols), and the like. Various FDA-approvedtopical inactive ingredients are found at the FDA's “The InactiveIngredients Database” that contains inactive ingredients specificallyintended as such by the manufacturer, whereby inactive ingredients canalso be considered active ingredients under certain circumstances.according to the definition of an active ingredient given in 21 CFR.210.3(b)(7). Alcohol is a good example of an ingredient that may beconsidered either active or inactive depending on the productformulation.

EXAMPLES

The following examples are presented for illustrative purposes only, andare not intended to limit the scope of the present invention in any way.The examples illustrate that 2MD, an analog of 1,25(OH)₂D₃ originallythought to be important in prevention and treatment of osteoporosis, isalso important in preventing and treating secondary hyperparathyroidismand its accompanying symptoms. A study conducted in rats in which theirkidneys were surgically removed, showed that daily oral andintraperitoneal (ip) 2MD administration results in lower levels of serumPTH, phosphorus, and creatinine, all indicators of kidney failure, ascompared to vehicle control animals. Furthermore, 2MD administrationresults in lower PTH, phosphorus and creatinine levels at dose levelsthat do not raise serum calcium.

Example 1

Materials and Methods

Nephrectomy Rat Model. Disease Induction. Weanling, male Sprague-Dawleyrats were obtained from Harlan (Madison, Wis.). Following a 10-13 dayacclimation period, the animals had two-thirds of one kidney removed.After a week, the other entire kidney was removed. The animals were thenswitched from a chow diet to a purified rodent diet (Suda et al.,Purified Rodent Diet-Diet 11) containing 0.6% Ca and 0.9% phosphorus andfat soluble vitamins A, D, E and K. Water and diet were provided adlibitum.

Animal Husbandry. Animals were housed in suspended, plastic shoe-boxstyle cages with corn cob bedding (prior to surgery) or in stainlesssteel, wire-bottom cages (approximately one week after surgery). Theanimal rooms were maintained at a temperature of 68 to 72° F. and arelative humidity of 25 to 75%. The holding rooms were set to provide 12hours of light per day.

Treatment Groups. Approximately four weeks after the second surgery,animals were assigned to treatment groups (14-15 animals/group) so thateach group had the same average PTH level.

Dose Preparation (Vehicle Formulation). The negative control materialwas prepared by volumetrically measuring ethanol (5%) and Neobee oil,mixing and then placing in storage at 2 to 8° C.

Dose Preparation (2MD Formulation). 2MD formulations (DP001, SigmaAldrich Fine Chemicals, Madison, Wis.) were prepared by firstdetermining the concentration of an ethanol stock solution using UVspectrophotometry (extinction coefficient=42,000; λ_(max)=252 nm). Thesolutions were then volumetrically added to Neobee oil so that there wasno more than 5% ethanol in the final solution. If necessary, additionalethanol was added to bring the final ethanol amount to 5%. The solutionwas mixed and stored at 2 to 8° C.

Dose Administration Method. Both vehicle and 2MD were administeredorally to the back of the tongue at 0.5 ml/kg body weight once daily for8 weeks, or intraperitoneally three times per week for 4 weeks.

Serum Parathyroid Hormone (PTH) Levels. By “serum PTH levels” we meanthe amount of PTH released by the parathyroid gland. PTH is the mostimportant regulator of the body's calcium and phosphorus levels, and iscontrolled by the level of calcium in the blood. Low blood calciumlevels cause increased PTH to be released, while high blood calciumlevels inhibit PTH release. Normal values are 10-55 picograms permilliliter (pg/mL). Four weeks after surgery and 4 and 8 weeks aftertreatment initiation, blood was collected from the tail artery and theconcentration of bioactive serum PTH was measured using the ratBioActive Intact PTH ELISA Kit from Immutopics, Inc. (San Clemente,Calif.).

Serum Calcium Analysis. Four weeks following surgery and 4 and 8 weeksafter treatment started, blood was collected from the tail artery ofeach experimental animal. The blood was allowed to coagulate at roomtemperature and then centrifuged at 3000×g for 15 minutes. The serum wastransferred to a polypropylene tube and stored frozen at −20° C. Thelevel of calcium was determined by diluting the serum into 0.1% lanthumchloride and measuring the absorbance on an atomic absorptionspectrophotometer (Perkin Elmer Model 3110, Shelton, Conn.).

Phosphorus Assay. Four weeks after surgery and 8 weeks after treatmentstarted, blood was collected from the tail artery of each experimentalanimal. The blood was allowed to coagulate at room temperature and thencentrifuged at 3000×g for 15 minutes. The serum was transferred to apolypropylene tube and stored frozen at −20° C. The level of phosphoruswas determined using a clinical analyzer (Pentra 400, Horiba ABXDiagnostics—France; UV method using phosphomolybdate).

Creatinine Assay. Measuring serum creatinine levels is a useful andinexpensive method of evaluating renal dysfunction. Creatinine is anon-protein waste product of phosphocreatinine metabolism by skeletalmuscle tissue. Creatinine production is continuous and is proportionalto muscle mass. Creatinine is freely filtered and therefore the serumcreatinine level depends on the Glomerular Filtration Rate (GFR). Renaldysfunction diminishes the ability to filter creatinine and the serumcreatinine rises. If the serum creatinine level doubles, the GFR isconsidered to have been halved. A threefold increase is considered toreflect a 75% loss of kidney function.

In the following examples, serum creatinine levels were evaluated fourweeks after surgery and 8 weeks after treatment started. Blood wascollected from the tail artery of each experimental animal. The bloodwas allowed to coagulate at room temperature and then centrifuged at3000×g for 15 minutes. The serum was transferred to a polypropylene tubeand stored frozen at −20° C. The level of creatinine was determinedusing a clinical analyzer (Pentra 400, Horiba ABX Diagnostics-France;Jaffe reaction) and is indicative of impaired renal function and chronicnephritis. In one embodiment of the invention, a minimum decrease inserum creatinine levels of approximately 30% is expected after treatmentaccording to the method of the present invention.

Example 2

Uremic Rat Model—Intraperitoneal (ip) Administration of 2MD

FIG. 1 schematically illustrates the ip treatment protocol with 2MD. Asshown in FIG. 2, ip administration of 2MD at 5 ng/kg bw three times perweek prevented increases in serum PTH, and suppresses circulating PTHlevels at 10 ng/kg bw. As shown in FIG. 3, ip administration of 2MD didnot raise serum calcium levels until a dose of 10 ng/kg bw wasadministered.

Example 3

Uremic Rat Model—Oral Administration of 2MD Compared to Zemplar®

FIG. 4 schematically illustrates the oral treatment protocol with 2MD.As shown in FIG. 5, oral administration of 2MD at daily doses of 1-5ng/kg bw prevented an increase or effected a reduction in serum PTHlevels. The observed effect lasted for eight weeks of therapy. As shownin FIG. 6, oral administration of Zemplar® at daily doses of 30-300ng/kg bw prevented an increase in serum PTH levels, but the therapeuticeffect was lost as the disease progressed. FIG. 7 illustrates that whenorally administered clinically significant serum calcium increases areobserved at 2MD doses of 5 ng/kg bw. FIG. 8 illustrates that when orallyadministered clinically significant serum calcium increases are observedat Zemplar® doses of 100 and 300 ng/kg bw.

As shown in FIG. 9, oral administration of 2MD at daily doses of 1-5ng/kg bw reduced serum phosphorus levels in nephrectomized rats. Incontrast, oral administration of Zemplar® did not reduce serumphosphorus levels in nephrectomized rats.

As shown in FIG. 11, oral administration of 2MD at daily doses of 1-5ng/kg bw resulted in lower serum creatinine levels compared to Vehiclecontrol animals. In contrast, oral administration of Zemplar® loweredserum creatinine levels compared to Vehicle control animals, however,only at dose levels that significantly increased serum calcium.

Example 4

Phase 1B Trial—Oral Administration of 2MD to Postmenopausal Women

FIG. 13 illustrates the oral administration of 2MD once daily for 28days to postmenopausal women at a dose of 110 nanograms (ng) reducedserum PTH levels by 21%, and a dose of 440 ng reduced serum PTH levelsby 67%.

Interpretation of Data

2MD or 2-methylene-19-nor-(20S)-1α,25-dihydroxyvitamin D₃ effectivelyreduces secondary hyperparathyroidism in a rat model of renal failure.Rats that have all but one sixth of their kidney mass surgicallyremoved, and are placed on a high phosphorus diet will develop elevatedPTH levels in the blood. Oral or intraperitoneal administration of 2MDon a daily or 3 times per week regimen will reduce the circulatinglevels of PTH. In addition, 2MD has the added benefit of preventingfurther increases or possibly reducing the levels of both phosphorus andcreatinine in the blood. Furthermore, 2MD exhibits long-lasting effectsin that rats treated orally for 8 weeks still show reduced PTH levels;whereas, other vitamin D compounds lose their effectiveness after 4weeks of treatment in this animal model.

We claim:
 1. A method of preventing secondary hyperparathyroidism in a subject at risk of developing secondary hyperparathyroidism comprising administering a therapeutically effective amount of 2-methylene-19-nor-(20S)-1α,25-dihydroxyvitamin D₃ or pharmaceutically acceptable salts thereof to the subject without inducing hypercalcemia in the subject wherein secondary hyperparathyroidism is prevented.
 2. The method of claim 1, wherein the 2-methylene-19-nor-(20S)-1α,25-dihydroxyvitamin D₃ is formulated in an oral, topical, transdermal, parenteral, injection or infusion dosage form.
 3. The method of claim 1, wherein the therapeutically effective amount ranges from about 20 ng/day to about 1 ug/day.
 4. The method of claim 1, wherein the therapeutically effective amount ranges from about 40 ng/day to about 600 ng/day.
 5. The method of claim 1, wherein the therapeutically effective amount ranges from about 50 ng/day to about 600 ng/day.
 6. The method of claim 1, wherein the therapeutically effective amount ranges from about 100 ng/day to about 400 ng/day.
 7. The method of claim 1, wherein the subject is receiving hemodialysis treatment.
 8. The method of claim 7, wherein the subject is administered a therapeutically effective amount of 2-methylene-19-nor-(20S)-1α,25-dihydroxyvitamin D₃ three times per week.
 9. A method for treating secondary hyperparathyroidism or the symptoms thereof in a subject having secondary hyperparathyroidism comprising administering a therapeutically effective amount of 2-methylene-19-nor-(20S)-1α,25-dihydroxyvitamin D₃ or pharmaceutically acceptable salts thereof to the subject without inducing hypercalcemia in the subject, wherein the secondary hyperparathyroidism or the symptoms thereof are treated.
 10. The method of claim 9, wherein the therapeutically effective amount ranges from about 20 ng/day to about 1 ug/day.
 11. The method of claim 9, wherein the therapeutically effective amount ranges from about 40 ng/day to about 600 ng/day.
 12. The method of claim 9, wherein the therapeutically effective amount ranges from about 50 ng/day to about 600 ng/day.
 13. The method of claim 9, wherein the therapeutically effective amount ranges from about 100 ng/day to about 400 ng/day.
 14. The method of claim 9, wherein the 2-methylene-19-nor-(20S)-1α,25-dihydroxyvitamin D₃ is formulated in an oral, topical, transdermal, parenteral, injection or infusion dosage form.
 15. The method of claim 9, wherein the subject is receiving hemodialysis treatment.
 16. The method of claim 15, wherein the subject is administered a therapeutically effective amount of 2-methylene-19-nor-(20S)-1α,25-dihydroxyvitamin D₃ three times per week.
 17. The method of claim 9, wherein the symptoms of secondary hyperparathyroidism are selected from the group consisting of serum PTH, serum phosphorus and serum creatinine.
 18. A method of preventing symptoms of secondary hyperparathyroidism in a subject at risk of developing symptoms of secondary hyperparathyroidism comprising administering a therapeutically effective amount of 2-methylene-19-nor-(20S)-1α,25-dihydroxyvitamin D₃ or pharmaceutically acceptable salts thereof to the subject without inducing hypercalcemia in the subject, wherein the symptoms of secondary hyperparathyroidism are prevented.
 19. The method of claim 18, wherein the 2-methylene-19-nor-(20S)-1α,25-dihydroxyvitamin D₃ is formulated in an oral, topical, transdermal, parenteral, injection or infusion dosage form.
 20. The method of claim 18, wherein the therapeutically effective amount ranges from about 20 ng/day to about 1 ug/day.
 21. The method of claim 18, wherein the therapeutically effective amount ranges from about 40 ng/day to about 600 ng/day.
 22. The method of claim 18, wherein the therapeutically effective amount ranges from about 50 ng/day to about 600 ng/day.
 23. The method of claim 18, wherein the therapeutically effective amount ranges from about 100 ng/day to about 400 ng/day.
 24. The method of claim 18, wherein the symptoms of secondary hyperparathyroidism are selected from the group consisting of serum PTH, serum phosphorus and serum creatinine.
 25. The method of claim 18, wherein the subject is receiving hemodialysis treatment.
 26. The method of claim 25, wherein the subject is administered a therapeutically effective amount of 2-methylene-19-nor-(20S)-1α,25-dihydroxyvitamin D₃ three times per week. 